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A 62-year-old healthy man felt unwell with chest pain, shortness of breath, and headaches the previous week. A complete blood count showed the following: hemoglobin, 95 g/L; leukocytes, 3.6 × 10 9/L; platelets, 41 × 10 9/L; myelocytes, 0.05 × 10 9/L; neutrophils, 2.35 × 10 9/L; blasts, 0.27 × 10 9/L; and nucleated red blood cells (2 per 100 white blood cells). He had no hepatosplenomegaly or lymphadenopathy, but an elevated lactate dehydrogenase concentration (560 U/L). Peripheral blood (PB) showed a leukoerythroblastosis with minimal anisopoikilocytosis. Flow immunophenotyping of PB showed 25% blasts, which were CD34 +/CD117 +/CD13 +/CD33 +/MPO –/CD56 +/CD4 –/CD41 –/CD61 –. Aspirate was unsuccessful. Biopsy was hypercellular with panmyelosis, including hyperproliferation of megakaryocytes with occasional hypolobated megakaryocytes, erythroid precursors, granulocytic precursors (panel A; original magnification ×20, hematoxylin and eosin stain), and MF-2 reticulin fibrosis (panel B; original magnification ×20, reticulin stain). Immunohistochemistry showed 40% to 50% CD34 + blasts in small aggregates/intrasinusoidal pattern (panel F; original magnification ×40). CD117/MPO (panel E; original magnification ×40), lysozyme/factor 8 (panel C; original magnification ×40), and E-cadherin/spectrin (panel D; original magnification ×40) confirmed the panmyelosis. PML/RARA, RUNX1/RUNX1T1, CBFB-MYH11, BCR/ABL1, and JAK2 on PB were negative. Acute panmyelosis with myelofibrosis (APMF) was contemplated initially. A PB cytogenetic analysis showed 50,XY,-3,-5,-7,+8,add(11)(q14-22),del(12)(p1?2),+21,+22,+mar1,+mar3,+mar4[5]/50,idem,-4,del(6)(q1?2?q25-27),-mar3,+mar5,+mar6[cp4]/46,XY[1]. These findings were consistent with acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) per 2008 and 2016 World Health Organization criteria.The distinction between AML-MRC and APMF can be very challenging, even with cytogenetics available, because both may have complex karyotypes; the presence of −5/del(5q) and/or −7/del(7q) confirms the diagnosis of AML-MRC as opposed to APMF. This case highlights the importance of PB cytogenetics in the context of dry tap due to fibrosis.
AML with myelodysplasia-related changes masquerades as acute panmyelosis with myelofibrosis
#00061158
Author: Zhaodong Xu
Category: Myeloid Neoplasms and acute leukemia (WHO 2016) > Acute Myeloid Leukemia > AML with multilineage dysplasia
Published Date: 12/18/2017
Category: Myeloid Neoplasms and acute leukemia (WHO 2016) > Acute Myeloid Leukemia > AML with multilineage dysplasia
Published Date: 12/18/2017
A 62-year-old healthy man felt unwell with chest pain, shortness of breath, and headaches the previous week. A complete blood count showed the following: hemoglobin, 95 g/L; leukocytes, 3.6 × 10 9/L; platelets, 41 × 10 9/L; myelocytes, 0.05 × 10 9/L; neutrophils, 2.35 × 10 9/L; blasts, 0.27 × 10 9/L; and nucleated red blood cells (2 per 100 white blood cells). He had no hepatosplenomegaly or lymphadenopathy, but an elevated lactate dehydrogenase concentration (560 U/L). Peripheral blood (PB) showed a leukoerythroblastosis with minimal anisopoikilocytosis. Flow immunophenotyping of PB showed 25% blasts, which were CD34 +/CD117 +/CD13 +/CD33 +/MPO –/CD56 +/CD4 –/CD41 –/CD61 –. Aspirate was unsuccessful. Biopsy was hypercellular with panmyelosis, including hyperproliferation of megakaryocytes with occasional hypolobated megakaryocytes, erythroid precursors, granulocytic precursors (panel A; original magnification ×20, hematoxylin and eosin stain), and MF-2 reticulin fibrosis (panel B; original magnification ×20, reticulin stain). Immunohistochemistry showed 40% to 50% CD34 + blasts in small aggregates/intrasinusoidal pattern (panel F; original magnification ×40). CD117/MPO (panel E; original magnification ×40), lysozyme/factor 8 (panel C; original magnification ×40), and E-cadherin/spectrin (panel D; original magnification ×40) confirmed the panmyelosis. PML/RARA, RUNX1/RUNX1T1, CBFB-MYH11, BCR/ABL1, and JAK2 on PB were negative. Acute panmyelosis with myelofibrosis (APMF) was contemplated initially. A PB cytogenetic analysis showed 50,XY,-3,-5,-7,+8,add(11)(q14-22),del(12)(p1?2),+21,+22,+mar1,+mar3,+mar4[5]/50,idem,-4,del(6)(q1?2?q25-27),-mar3,+mar5,+mar6[cp4]/46,XY[1]. These findings were consistent with acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) per 2008 and 2016 World Health Organization criteria.The distinction between AML-MRC and APMF can be very challenging, even with cytogenetics available, because both may have complex karyotypes; the presence of −5/del(5q) and/or −7/del(7q) confirms the diagnosis of AML-MRC as opposed to APMF. This case highlights the importance of PB cytogenetics in the context of dry tap due to fibrosis.
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